The character of the cracks is more variable than in Loxa Bark, few extending to the whole circumference of the bark ; in the young pieces the cracks are not so deep as in the older, in which also the edges are raised, giving a rough appearance to it Some specimens also between the large and extensive cracks present spaces very slightly cracked, of a golden-straw or leaden-gray colour. Huanuco Bark is distinguished by the brighter colour of its surface, the multi tude of its small cracks, and the sharp oblique incisions above mentioned, from the yellow or Calisaya bark (Quinn regia), and the Lox* bark, to both of which it bears considerable resemblance. The inner surface is of a bright-cinnamon, passing into an ochre-yellow or rusty hue, and is generally rough, and, especially in the thicker quills, fibrous, frequently with portions of the wood of the stem adhering to it Though no satisfactory chemical analysis has been made of it, exhibiting its entire composition, yet the relative proportions of its alkaloids have been stated. It is the richest in Cinchonia of all the barks hitherto examined. Goebel, Kirst, and Von Santen say that it yields this alkaloid only. Michaelis maintains that two specimens analysed by him yielded, in addition, a little Quinia. The quantity of Cinchonia is very variable. Kirst and Goebel obtained from one pound 168 grains; Von Santen from nine different specimens examined by him, from one pound a quantity varying from 1061 grains to 210 grains. The fracture of the bark is either fibrous or splintery ; that of the outer portion resinous. Tho odour resembles that of clay. Tho taste acid, astringent, somewhat aromatic ; then bitter, acrid, and enduring. The powder is a deep cinnamon-brown.
3. The third kind of palo bark, called Ash, Jaen, or by corruption Ten-Bark, is by Von Bergen referred to C. orate (It. and 1'.), which he censidera aynonymons with the C. puhescena of Vahl. It is likewise called Palo Ten-Bark to distinguish it from the Dark Ten-Bark, or False Loxa Bark. The quills of this kind are always crooked, frequently also twisted. The epidermis is frequently absent; when present, it presents faint transverse cracks, the edges of which are somewhat raised, and a few longitudinal cracks or warts. The bark itself is of an ash-gray, whitish-gray, or light-yellow colour, with brown or blackish sprats. It has often a slightly alibiing aspect. The inner surface varies very much, sometimes smooth, sometimea with long fibres attached to it, sometimes splintery, of a cinnamon or dark brown colour. The fracture is sometimes even, sometimes slightly fibrous, with a faint external resinous circlet The odour ia a little like tan, and pleasant. The taste slightly acid and moderately astringent, a pure but not disagreeable bitter. The accounts of its chemical composition diger mush. Von Santen says it contains neither Cinchonia nor Quinia. Goebel and Kirst from one pound obtaiued no Cinchonia, but 12 grains of Quinia; while 31ichaelis says in two specimens examined by him, he found both Quinia and Chin amnia ; of the former, even 80 grains ; of the latter, 12 grains. Notwith standing this last statement, this is generally and justly regarded ns a very bad sort of pale bark, and was chiefly used to adulterate the true Loxa Bark.
The Dark Ten-Bark, or China Psoudo-Loxa, occurs generally in thin or middle-sized, but seldom thick, quills. The surface exhibits trans verse create and longitudinal wrinkles, which often form rings a lino or more broad. The colour is milk-white, but covered with so many lichens as to have a dark appearance. The under surface is uneven, fibrous or splintery, the fibres often very long: the colour a rusty brown. The fracture is fibrous or splintery: it exhibits a resinous appearance only when cut Smells strongly like tan. Thu taste at first enduringly acid, afterwards astringent This bark is frequently purchased instead of the true Loxa Bark, and is at present of fre quent occurrence in the market. Bergen considers it to be produced
by the C. nitida (It. and P.) and the C. lancifolia : these are perhaps only varieties the one of the other ; but whenceever obtained it is very poor in alkaloids, one pound yielding only P grains of Kilda and 12 of Cinchonia. It is held to be one of the worst kinds of pale bark.
The lichens and epidermis should be scraped off all pale Mirka before they are reduced to powder: though they increase the bulk, they diminish the of the powder.
The Yellow Barks.—There are only throe kinds; the Yellow Bark of English commerce, which by continental writers is called merely China regia, Quince Ca Usage (the Quinquina Royal, Gelbe Ki;nigachina), and the Yellow or Carthagena Btu* of the Continent comprehending two sorts :-1. China flare fibrosis, China de Carthagena fibrosis, the Quinn is'aranjada (of the natives); the Quina de Santa Fe fibroma, or Quills de Carthagena leuosa (fibrosis), of the Spanish; Quinn de Carthagena amarella leuhosa (fibrosis) of the Portuguese; Quinquina de Cartha gene fibreux, ligneux, Quinquina Orange (of the French); Holzige Gelbe China, Holzige Carthagenarinde (of the Germans). 2. China flava dura, China lutes, China de Carthagena dura, Quinn Naranjada de Santa Fe, Quina aurantiaca, Quills de Santa F6, or Quinn de Car thagena dura (Spanish); Quina de Cartagena amarilla dura (Portuguese); Quinquina de Carthagene, or Quinquina flava darn (French); lliu-to Gelbe China, Harte Carthagenarinde. This is the Orange Bark of Mutia, which he says is obtained from C. lancifolia. Bergen and Goebel ascribe it to C. cordifolia (Mali), which some deem synony mous with C. pubescens (Vahl.), which species is therefore stated alone to yield the yellow bark ; but this only applies to the yellow bark of the Continent, for the source of the Yellow Bark of English corn coerce must be considered as yet undetermined. We shall limit our description to this last kind, as the best known in this country, and at the same time the most valuable. Thisoccurs in two forina—quillsand flat-pieces; the quills were formerly most prized, but all well-informed persons now prefer the flat pieces as much richer in Quinis. The quills are in general in single, seldom in double rAle, the diameter of which is mostly greater than even the largest quills of pale Loxa Bark, being from is quarter of an inch to an inch, the length from 4 to 24 inches, occasionally containing smaller quills inside the larger. The thickness of the bark varies from one-eighth to one-fourth of an inch. The external surface is generally grayish-brown, inclining to blackish, yellowish, or whitish, according to the kind of lichen by which it is beset. Few pieces are quite free from lichens ; many specimens exhi bit the wax-yellow thallus of Lepra Aare (Ache.), which appears as if fumed upon it : this is a very characteristic mark, when present, of Calisaya bark. The quills seldom have the epidermis removed, which has both transverse and longitudinal cracks, which penetrate down to the bark itself, as their traces can be perceived upon it even when the epidermis has been removed. The transverse cracks frequently extend over the whole circumference of the piece, yet they are much inter rnpted by longitudinal cracks and furrows (this is more especially the case with the thinnest quills); but all of them have raised edges, resembling those of Loxa Bark. Where the epidermis is wanting, the colour of the exposed part is of a cinnamon or rusty-brown hue. The colour of the inner surface varies according to the age of the bark. Generally it is a deep cinnamon, in recent barks verging to reddish ; in older specimens it is paler, or a rusty-yellow. The transverse frac ture is in the thinner quills smooth, in the larger fibrous, splintery, or vitreous; a resinous circle is under the epidermis. The longitudinal fracture is generally uneven, and delicately fibrous : this kind of bark is easily broken.